inquires about Motorized Book Cart

[Ishah]

Hello and Hi,

I'm planed to do a book cart electronic similar as attached

Since, Im lack of software,I took a long time for Programming in MicroC but for simulation in ISIS Proteus,seem it works. But to do the real, I got some conflict and stuck.

I want to drive 2 DC Motor(connected to right and left wheel) with 12 volts battery rechargeable & Micro-controller circuitry related as attached. (PIC16F877A+L293D)
.

My question;
- Should I drive 2 DC motor or just one?
- It is my motor driver L293D capable or need other IC?
- What type of DC motor that robust with L293D and it can carry the max load of 700kg. What calculation i should aware?


Please help and need suggestion.

 

[chuckey]

" the max load of 700kg. ", this is bigger then a golf buggy! it is the weight a small car so you would need 10-20 HP to make it move at all. You will have all sort of mechanical problems.
Frank

 

[Ishah]

it is the weight a small car so you would need 10-20 HP to make it move at all. You will have all sort of mechanical problems.

It is only roughly estimation, since I think to consider about the trolley and also book/journal weight. :roll: Really need your advice. Should I estimate lower, 500kgs maybe?

What do you mean by 10-20 HP? Can you guide me, what I should do to face the mechanical part, Im lack of that.

 

[chuckey]

"What do you mean by 10-20 HP? ", HP = Horse power, 1 HP = .752 kW. I think you want to Google " Golf buggy" and try and find the rough size of their motors/ batteries and all up weight. You could try " electric buggy" / " electric cart". . . Another tack would be to research "mobility scooter", these are for carrying disabled people about. Do you really want to move 700 kg of books about?
Frank

 

[Ishah]

Hi Frank,

I think I should reduce the weight, 300kg. I don't want to make something like buggy.Its too hard.I want to make just simple trolley that used in library. It would help librarians to moving the trolley easily, without use lots energy. Can you guide to make the mechanical part... how about the type of wheel and motor i should use? What calculation i should aware?

 

[chuckey]

From googling " mobility scooter" model :- Active care Catalina. Instruction manual . this carries a person up to 4 MPH, with 10" diam wheel rims (have to add abit for the tyre thickness)
Motor Two 24V x 320W x 4600rpm
Controller Dynamic A50A
Batteries Two DC12V x 36AH
Soo, 2 X 320 W = 640 W, using your 12V battery = 640/12 = 53 A.
Wheel centre = 10", = 14" diam over tyre. So in one revolution does PI X 14 inches ~ 40 ", So for 4 MPH wheel does 4 X 5280 X 12/40 REVs ~ 6336 revs in an hour, so does ~ 100 RPM, so motor is rated at 4600, wheels need 100 RPM max so gear ratio is 46 :1.
So to under line the points, to carry a person (200lbs ~ 80 Kg) at 4 MPH (stiff walking pace), you need to drag a peak current of 50 A from a 12 V and use a 40 :1 reduction gearbox between the motor and 14" (overall diameter) wheels.
I am not sure that the kit you have is up to this.
Frank